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Mazda Engine General \  About my carb problems.

About my carb problems.

Mazda Engine General Mazda Engine Mazda Tech
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zaccutt   +1y
Ok if you have been following any of my posts you would have heard that my truck that I rebuilt the motor and all is having trobles with the carb.

I am trying to understand whats going on.

I think this is the problem as of yet, My truck went into the shop with a stalling issue (stalled when there was no gas applied until the motor was warmed up.) It came out stalling in the same way except it never stopped when the motor got warm.

The mechanic said the carb heating plate wasn't hooked up and wasn't working. I think what hasppend is this. I put an aftermarket rad in the truck and it had a spot for a sensor at the top of the rad. This sensor was for a trhermal switch to run the electric fan. Well when I took the fan back off I left the switch in the hole obviously to plug it. I think he thought that the carb heater plate was supposed to be hooked up to that. I want to now change it back to the way it is supposed to be wired. (He came to the conclusion that that switch is broken, then I realized its not even supposed to be hooked up to it! SO I got the truck back not fixed and still paid him his money )

So basically I need to know what the carb heater is (pictures would be great) and how exactly it can be wired up.

I think this is the best thing to do for now so I can atleast drive it then I will deal with the emissions bs.

If this fixes the stalling problem I would be surprised but I think its a good start.

If you have any info on this please let me know.

Thanks!

Zac
framedragger2   +1y
your base plate heater should have a single wire hook up that runs off a 12v supply that is kicked on when the key is on, i didnt see where you were from but it shouldnt be that big of a problem unless where you live gets really cold, but ne wayz c if you can find a wiring diagram for your truck and find the red wire that is close to your intake runner, it comes from the harness running beside your carb/plenum.
nytrdr24   +1y
the carb heater is a little black spacer plate w/ a coil that goes inbetween the carb & the intake manifold....it is hooked up to a wire in the harness that hooks up all of that emissions crap to the carb...only one wire, i think it was red, and ran down to the alternator, could be wrong tho....if this is hooked to the switch on the rad, neither should be working, especially if you unhooked the switch when you removed the elect fan.....now, there is a thermal switch that goes in the bottom of the stock rad, which in some shape-form-or-fashion controls the a/c compressor kicking in & out if i'm not mistaken

the carb heater is supposed to warm the air/fuel mixture enough to keep it from freezing up the carb, if it isn't hooked up, that could be the cause of your truck stalling, especially in cold weather....it will need to be hooked up back like it was from the factory, if i'm not mistaken it requires less than 12v for proper operation....
zaccutt   +1y
Ok, so first off, I live in Canada and it is cold here right now. I swapped the wire for the heater with the red one and it runs much better. It still stalls when its first warming up but not as bed and I was able to bump start it for most of the 3-4 times that it did stall. Would this be normal for a 91' B2200 that is carbed? What else do you think it could be?

One other problem I had was when I pulled in my driveway after a good 10minute cruise right when I got to the garage and stopped it stalled. I then restarted it without my foot near the gas at all and it started then slowly gained revs until I definately thought it was reving too high. So I just revved the engine once and it died back down to a normal rpm. Sounds to me like the choke was sticking or something.

But all in all its going well. I think I will pull off the air cleaner and check if the choke is working right like BJ said in the other topic.

Lastly, I am pretty sure i is but how exactly would you check if the carb heater is working right? I would assume it is because of how much better it is running now.

Zac
dropped90(justin)   +1y
sounds like you are having choke problems to me.




-justin
89b2200   +1y
Let's see if I can help.

The PTC heater will be ON only if the temperature switch under the radiator is closed. The switch closes at 50F or below ambient temp. If you turn the ignition to ON without starting, the heater plate will get energized and will warm up the carb.

On your stalling issue, you are in the right track, check to make sure your choke is working. Before starting the truck, floor the gas pedal and that will close the choke plate. When you start the truck and get it idling with a cold engine, it should idle high at 15oo rpm. As the engine is running, the choke heater will get energized by the alternator and gradually open the choke just in time when the engine gets up to operating temp. Then when you blip the gas pedal, idle should drop to 800 rpm. Check that first.
hocbj23   +1y
I think all this was covered in posts in response to your "At the end of my rope" thread,Zac.Why repost?Just continue that thread OR read the f'ing posts in your original thread.It takes folks time and effort to go over the same sh-- multiple times especially when the info is the same.Or if u dont believe what we said in the original post,call bullsh-- and out us for not knowing what we are talking about.I,for one know what the f--- I'm talking about and so do most of the others on here.Jesus.BJ
lofosho86   +1y
Easy hoc!dont stroke out on us!!lol j/k
zaccutt   +1y


The reason I reposted this is because the other topic had a whole bunch of nonsense in it not related to the problem. I said in the other topic that I started a fresh one to deal with these problems (I even posted a link in it directing people about the problem to here.) and a few posts up I even said I am going to try your suggestions.

Not to mention maybe this way people can actually find relevant information if they search "carb problems." (And it wont be in an off topic forum with a random name.)

I know you know what your talking about and took your advice and have started using it.

The other post was more directed towards my emissions problems and more or less a rant, this one is the problem with the carb and stalling.

I think this repost is fully justified.

As for my truck, 89b2200, I tried what you said, I first put the gas all the way down and then when I started it it revved at what I would assume sounds like 1500rpm (No tach) and I let it sit for a minute or two and it revved like that fine. I then blipped the gas and it dropped down to what I would also assume sounded about 800rpm. I then decided to take it out for a test drive and it ran completely normally around the block and back with not a single problem.

I am going to take the truck to school tomorrow and I will let you all know how it turns out.

Thank you everyone who has contributed.
Zac
Post was last edited on Dec 18, 2007 01:12. This post has been edited 1 times.
zaccutt   +1y
delete
Post was last edited on Feb 06, 2008 01:02. This post has been edited 1 times.